I don't know anything about 1 or 3, but with #2, the answer seems to be that they're the same lens (unless I'm missing something) but that one is "new" and the other is a demo - an "open box special." Opinions vary on whether people testing the lens in the store runs enough risk of damaging or degrading it to the point where it's not worth buying. With B&H, I'd probably trust them enough to save the $30, but that's up to you.

Now that I have that out of the way, let me take a shot at my OPINION on the options you stated.

1) if you have the money, the 28-105 is a better lens than the 18-55. Both are slow, but the 28-105 is a decent lens for the money. There are others out there as well in this price range that may be better.

2) The second link is a Demo item... which means it was used by somebody to demonstrate the lens. Both have a 5 year warranty.

3) Phoenix is absolute garbage, IMHO. Junk. Trash. Horrible. Run away from them. If you are going to get a third-party lens, look at Tamron, Sigma, Tokina or some brand you have heard of.